Achieving collision avoidance and fairness in CSMA-based wireless mesh networks

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Abstract/Contents

Abstract
CSMA-based wireless mesh networks are vulnerable to collisions. Even a single unicast flow can exhibit excessive collisions from hidden terminals. Furthermore, fairness objectives for single-hop networks can cause undesirable behaviors for mesh networks. Mesh networks of wireless sensors suffer from undesirable protocol interactions due to these challenges. Inter-protocol collisions and unfair channel usage between protocols cause the behavior of one protocol to change depending on other protocols. These inter-protocol interactions complicate the design of large sensor network systems. Motivated by these problems, this dissertation presents grant-to-send, a novel collision avoidance mechanism for wireless mesh networks. Rather than announce packets it intends to send, a node using grant-to-send announces packets it expects to hear others send. This dissertation provides evidence that inverting collision avoidance in this way greatly improves wireless mesh performance without significant overhead. Grant-to-send is simple to implement, and is compatible with existing hardware. Grant-to-send is also general enough to replace protocol-specific collision avoidance mechanisms common to sensor network protocols. While these individual mechanisms only avoid intra-protocol collisions, grant-to-send provides a MAC mechanism which can address both intra- and inter-protocol collisions. This dissertation also proposes a fairness scheme for mesh networks, which can be applied to protocol fairness. The fairness scheme combines and modifies traditional flow-based fairness techniques such as fair queueing and fair scheduling. However, the complexities of wireless make these mechanisms insufficient by themselves. This dissertation therefore proposes two new mechanisms that address these limitations, channel decay and fair cancellation, and shows that the fairness scheme can significantly improve protocol fairness. Together, this dissertation shows that achieving collision avoidance and fairness can make mesh networks perform better, more reliable, and thus easier to design.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2011
Issuance monographic
Language English

Creators/Contributors

Associated with Choi, Jung Il
Associated with Stanford University, Department of Electrical Engineering
Primary advisor Levis, Philip
Thesis advisor Levis, Philip
Thesis advisor Katti, Sachin
Thesis advisor Tobagi, Fouad A, 1947-
Advisor Katti, Sachin
Advisor Tobagi, Fouad A, 1947-

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Jung Il Choi.
Note Submitted to the Department of Electrical Engineering.
Thesis Ph.D. Stanford University 2011
Location electronic resource

Access conditions

Copyright
© 2011 by Jung Il Choi

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